Liquid crystal display (LCD) devices are used in a variety of applications, such as in televisions, computer monitor display devices, tablet display devices, mobile phones, and smart phone displays. They are energy efficient when compared with other types of displays, and they can be thinner than many other types of displays. Most LCDs include a layer of liquid crystal molecules aligned between two transparent electrodes, and two polarizing filters. Light from a light source is provided to the LCD, and the amount of light from the source that passes through the LCD can be controlled by controlling an electric field between the two transparent electrodes, which, in turn, controls the orientation of the liquid crystal molecules and therefore the amount of light that passes through the LCD.
An LCD device can include many individually-controllable pixel elements. By controlling the amount of light that is transmitted through each element, an image can be defined by the LCD device. In addition, the pixel elements may include multiple different color filters, where the amount of white light passing through each filter can be individually-controlled, so that the LCD device can render a color image.
The amount of light that is transmitted through each pixel element of an LCD device can be controlled in a variety of ways. For example, the opacity of individual color filters of individual pixels can be controlled to create different colors, and different brightnesses, at the locations of different pixels of the device. In addition, the intensity of the backlight that supplies light to the LCD can be varied to control the maximum brightness that can be achieved at a pixel element that is illuminated by the backlight. Bright backlight intensities may permit the LCD device to achieve a high dynamic range of colors and brightnesses that can be produced in an image displayed to a viewer. However, the amount of light that is ultimately passed through the polarizing layers and color filter layers of the LCD display to a viewer of the display compared with the amount of light produced by the backlight can be relatively small, which results in high power consumption by the device that uses the display.
Another approach to displays used in televisions, computer displays, phone displays, etc. involves the use of field-sequential systems that rely on MEMS (“microelectromechanical systems”) technology to pass different color components of white light through pixel elements of the display. By controlling the amounts of the different color components that are passed through a pixel element and by cycling through the different color components at a rate that is fast compared to the response rate of human vision, a color of a pixel element can be controlled. MEMS shutters that have a size on the order of the size of a pixel element of the display can opened and closed to selectively allow different amounts of the different color components to pass through the pixel element. Until recently, the rate at which MEMS shutters could be opened and closed limited the quality of field-sequential displays, because when the shutters could not open and close fast enough compared to the response rate of human vision, a person would see annoying color fringes in the display when moving their eyes with respect to the display. However, recent advances in MEMS-based shutters—specifically, the rate at which they can be opened and closed—have improved the quality of field-sequential displays.